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• Looking for advice on Hyper-v storage replication

  - by Notre1

  I am designing a 2-host Hyper-V R2 cluster with 6-10 guests stored on a SMB iSCSI SAN device (probably Promise VessRAID). I will be getting at least two of the SAN devices and need to eliminate the storage a single point of failure. Ideally, that would involve real-time failover for the storage, like the Windows failover clustering does for the hosts. This design will be used at around six of our sites, and I would like to allow for us to eventually setup a cluster at colocation site and replicate each site's VMs there for DR. (Ideally a live multi-site cluster, but a manual import of the VMs would be fine for this sort of DR.) The tools that come with enterprise SANs, like EMC and NetApp, seem to be the most commonly used items for a Hyper-V cluster, but I can't afford their prices with my budget. Outside of them, the two tools that seem to be most common for Hyper-V storage replication are SteelEye (now SIOS) DataKeeper Cluster Edition and Double-Take Availability. Originally, I was planning on using Clustered Shared Volume(s) (CSV), but it seems like replication support for these is either not available or brand new in both these products. It looks like CSVs are supported in Double-Take 5.22, see this discussion, but I don't think I want to run something that new in production. Right now, it seems like the best option for me is not to implement CSVs, implement some sort of storage replication, and upgrade to CSVs at a later date once replicating them is more mature. I would love to have live migration, and CSVs are not required for live migration if you are using one LUN per VM, so I guess this is what I'll do. I would prefer to stick to the using the Microsoft Windows Server and Hyper-V tools and features as much as possible. From that standpoint, SteelEye looks more appealing than Double-Take because they make the DataKeeper volume(s) available to the Failover Clustering Manager and then failover clustering is all configured and managed through the native Microsoft tools. Double-Take says that "clustered Hyper-V hosts are not supported," and Double-Take Availability itself seems to be what is used for the actual clustering and failover. Does anyone know if any of these replication tools work with more than two hosts in the cluster? All the information I can find on the web only uses two hosts in their examples. Are there any better tools than SteelEye and Double-Take for doing what I am trying to do, which is eliminate the storage as as single point of failure? Neverfail, AppAssure, and DataCore all seem to offer similar functionality, but they don't seems to be as popular as SteelEye and Double-Take. I have seen a number of people suggest using Starwind iSCSI SAN software for the shared storage, which includes replication (and CSV replication at that). There are a couple of reasons I have not seriously considered this route: 1) The company I work for is exclusively a Dell shop and Dell does not have any servers with that I can pack with more than six 3.5" SATA drives. 2) In the future, it could be advantegous for us to not be locked into a particular brand or type of storage and third-party replication softwares all allow replication to heterogeneous storage devices. I am pretty new to iSCSI and clustering, so please let me know if it looks like I am planning something that goes against best practices or overlooking/missing something.

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• Looking for advice on Hyper-v storage replication

  - by Notre1

  I am designing a 2-host Hyper-V R2 cluster with 6-10 guests stored on a SMB iSCSI SAN device (probably Promise VessRAID). I will be getting at least two of the SAN devices and need to eliminate the storage a single point of failure. Ideally, that would involve real-time failover for the storage, like the Windows failover clustering does for the hosts. This design will be used at around six of our sites, and I would like to allow for us to eventually setup a cluster at colocation site and replicate each site's VMs there for DR. (Ideally a live multi-site cluster, but a manual import of the VMs would be fine for this sort of DR.) The tools that come with enterprise SANs, like EMC and NetApp, seem to be the most commonly used items for a Hyper-V cluster, but I can't afford their prices with my budget. Outside of them, the two tools that seem to be most common for Hyper-V storage replication are SteelEye (now SIOS) DataKeeper Cluster Edition and Double-Take Availability. Originally, I was planning on using Clustered Shared Volume(s) (CSV), but it seems like replication support for these is either not available or brand new in both these products. It looks like CSVs are supported in Double-Take 5.22, see this discussion, but I don't think I want to run something that new in production. Right now, it seems like the best option for me is not to implement CSVs, implement some sort of storage replication, and upgrade to CSVs at a later date once replicating them is more mature. I would love to have live migration, and CSVs are not required for live migration if you are using one LUN per VM, so I guess this is what I'll do. I would prefer to stick to the using the Microsoft Windows Server and Hyper-V tools and features as much as possible. From that standpoint, SteelEye looks more appealing than Double-Take because they make the DataKeeper volume(s) available to the Failover Clustering Manager and then failover clustering is all configured and managed through the native Microsoft tools. Double-Take says that "clustered Hyper-V hosts are not supported," and Double-Take Availability itself seems to be what is used for the actual clustering and failover. Does anyone know if any of these replication tools work with more than two hosts in the cluster? All the information I can find on the web only uses two hosts in their examples. Are there any better tools than SteelEye and Double-Take for doing what I am trying to do, which is eliminate the storage as as single point of failure? Neverfail, AppAssure, and DataCore all seem to offer similar functionality, but they don't seems to be as popular as SteelEye and Double-Take. I have seen a number of people suggest using Starwind iSCSI SAN software for the shared storage, which includes replication (and CSV replication at that). There are a couple of reasons I have not seriously considered this route: 1) The company I work for is exclusively a Dell shop and Dell does not have any servers with that I can pack with more than six 3.5" SATA drives. 2) In the future, it could be advantegous for us to not be locked into a particular brand or type of storage and third-party replication softwares all allow replication to heterogeneous storage devices. I am pretty new to iSCSI and clustering, so please let me know if it looks like I am planning something that goes against best practices or overlooking/missing something.

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• Importing Multiple Schemas to a Model in Oracle SQL Developer Data Modeler

  - by thatjeffsmith

  Your physical data model might stretch across multiple Oracle schemas. Or maybe you just want a single diagram containing tables, views, etc. spanning more than a single user in the database. The process for importing a data dictionary is the same, regardless if you want to suck in objects from one schema, or many schemas. Let’s take a quick look at how to get started with a data dictionary import. I’m using Oracle SQL Developer in this example. The process is nearly identical in Oracle SQL Developer Data Modeler – the only difference being you’ll use the ‘File’ menu to get started versus the ‘File – Data Modeler’ menu in SQL Developer. Remember, the functionality is exactly the same whether you use SQL Developer or SQL Developer Data Modeler when it comes to the data modeling features – you’ll just have a cleaner user interface in SQL Developer Data Modeler. Importing a Data Dictionary to a Model You’ll want to open or create your model first. You can import objects to an existing or new model. The easiest way to get started is to simply open the ‘Browser’ under the View menu. The Browser allows you to navigate your open designs/models You’ll see an ‘Untitled_1′ model by default. I’ve renamed mine to ‘hr_sh_scott_demo.’ Now go back to the File menu, and expand the ‘Data Modeler’ section, and select ‘Import – Data Dictionary.’ This is a fancy way of saying, ‘suck objects out of the database into my model’ Connect! If you haven’t already defined a connection to the database you want to reverse engineer, you’ll need to do that now. I’m going to assume you already have that connection – so select it, and hit the ‘Next’ button. Select the Schema(s) to be imported Select one or more schemas you want to import The schemas selected on this page of the wizard will dictate the lists of tables, views, synonyms, and everything else you can choose from in the next wizard step to import. For brevity, I have selected ALL tables, views, and synonyms from 3 different schemas: HR SCOTT SH Once I hit the ‘Finish’ button in the wizard, SQL Developer will interrogate the database and add the objects to our model. The Big Model and the 3 Little Models I can now see ALL of the objects I just imported in the ‘hr_sh_scott_demo’ relational model in my design tree, and in my relational diagram. Quick Tip: Oracle SQL Developer calls what most folks think of as a ‘Physical Model’ the ‘Relational Model.’ Same difference, mostly. In SQL Developer, a Physical model allows you to define partitioning schemes, advanced storage parameters, and add your PL/SQL code. You can have multiple physical models per relational models. For example I might have a 4 Node RAC in Production that uses partitioning, but in test/dev, only have a single instance with no partitioning. I can have models for both of those physical implementations. The list of tables in my relational model Wouldn’t it be nice if I could segregate the objects based on their schema? Good news, you can! And it’s done by default Several of you might already know where I’m going with this – SUBVIEWS. You can easily create a ‘SubView’ by selecting one or more objects in your model or diagram and add them to a new SubView. SubViews are just mini-models. They contain a subset of objects from the main model. This is very handy when you want to break your model into smaller, more digestible parts. The model information is identical across the model and subviews, so you don’t have to worry about making a change in one place and not having it propagate across your design. SubViews can be used as filters when you create reports and exports as well. So instead of generating a PDF for everything, just show me what’s in my ‘ABC’ subview. But, I don’t want to do any work! Remember, I’m really lazy. More good news – it’s already done by default! The schemas are automatically used to create default SubViews Auto-Navigate to the Object in the Diagram In the subview tree node, right-click on the object you want to navigate to. You can ask to be taken to the main model view or to the SubView location. If you haven’t already opened the SubView in the diagram, it will be automatically opened for you. The SubView diagram only contains the objects from that SubView Your SubView might still be pretty big, many dozens of objects, so don’t forget about the ‘Navigator‘ either! In summary, use the ‘Import’ feature to add existing database objects to your model. If you import from multiple schemas, take advantage of the default schema based SubViews to help you manage your models! Sometimes less is more!

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• Will this force a reinitialize in Merge Replication Topology?

  - by Refracted Paladin

  I need to add a couple of columns to a table that is a part of a replication set. It is not a constraint coulumn or a part of any article filters and it allows NULL. I have a pretty good idea that I can run this -- ALTER TABLE tblPlanDomain ADD ReportWageES VARCHAR (100) NULL and NOT force all my clients to reinitialize but I was hoping for some reassurance. Can anyone verify this one way or the other for me? Thanks,

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• Path of Replication

  - by geeko

  I'm currently developing a replication system to keep data in-synch between an arbitrary number of servers. Some of these servers exist in one cluster on one LAN. Others exist somewhere else in the world. I'm wondering what are the pros/cons of different paths that we choose to flow replicated data on between servers? In other words, what are the different strategies to load balance the replication process ?

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• Deploying Data Mining Models using Model Export and Import, Part 2

  - by [email protected]

  In my last post, Deploying Data Mining Models using Model Export and Import, we explored using DBMS_DATA_MINING.EXPORT_MODEL and DBMS_DATA_MINING.IMPORT_MODEL to enable moving a model from one system to another. In this post, we'll look at two distributed scenarios that make use of this capability and a tip for easily moving models from one machine to another using only Oracle Database, not an external file transport mechanism, such as FTP. The first scenario, consider a company with geographically distributed business units, each collecting and managing their data locally for the products they sell. Each business unit has in-house data analysts that build models to predict which products to recommend to customers in their space. A central telemarketing business unit also uses these models to score new customers locally using data collected over the phone. Since the models recommend different products, each customer is scored using each model. This is depicted in Figure 1.Figure 1: Target instance importing multiple remote models for local scoring In the second scenario, consider multiple hospitals that collect data on patients with certain types of cancer. The data collection is standardized, so each hospital collects the same patient demographic and other health / tumor data, along with the clinical diagnosis. Instead of each hospital building it's own models, the data is pooled at a central data analysis lab where a predictive model is built. Once completed, the model is distributed to hospitals, clinics, and doctor offices who can score patient data locally.Figure 2: Multiple target instances importing the same model from a source instance for local scoring Since this blog focuses on model export and import, we'll only discuss what is necessary to move a model from one database to another. Here, we use the package DBMS_FILE_TRANSFER, which can move files between Oracle databases. The script is fairly straightforward, but requires setting up a database link and directory objects. We saw how to create directory objects in the previous post. To create a database link to the source database from the target, we can use, for example: create database link SOURCE1_LINK connect to <schema> identified by <password> using 'SOURCE1'; Note that 'SOURCE1' refers to the service name of the remote database entry in your tnsnames.ora file. From SQL*Plus, first connect to the remote database and export the model. Note that the model_file_name does not include the .dmp extension. This is because export_model appends "01" to this name.  Next, connect to the local database and invoke DBMS_FILE_TRANSFER.GET_FILE and import the model. Note that "01" is eliminated in the target system file name.  connect <source_schema>/<password>@SOURCE1_LINK; BEGIN  DBMS_DATA_MINING.EXPORT_MODEL ('EXPORT_FILE_NAME' || '.dmp',                                 'MY_SOURCE_DIR_OBJECT',                                 'name =''MY_MINING_MODEL'''); END; connect <target_schema>/<password>; BEGIN  DBMS_FILE_TRANSFER.GET_FILE ('MY_SOURCE_DIR_OBJECT',                               'EXPORT_FILE_NAME' || '01.dmp',                               'SOURCE1_LINK',                               'MY_TARGET_DIR_OBJECT',                               'EXPORT_FILE_NAME' || '.dmp' );  DBMS_DATA_MINING.IMPORT_MODEL ('EXPORT_FILE_NAME' || '.dmp',                                 'MY_TARGET_DIR_OBJECT'); END; To clean up afterward, you may want to drop the exported .dmp file at the source and the transferred file at the target. For example, utl_file.fremove('&directory_name', '&model_file_name' || '.dmp');

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• Abstract Data Type and Data Structure

  - by mark075

  It's quite difficult for me to understand these terms. I searched on google and read a little on Wikipedia but I'm still not sure. I've determined so far that: Abstract Data Type is a definition of new type, describes its properties and operations. Data Structure is an implementation of ADT. Many ADT can be implemented as the same Data Structure. If I think right, array as ADT means a collection of elements and as Data Structure, how it's stored in a memory. Stack is ADT with push, pop operations, but can we say about stack data structure if I mean I used stack implemented as an array in my algorithm? And why heap isn't ADT? It can be implemented as tree or an array.

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• If a SQL Server Replication Distributor and Subscriber are on the same server, should a PUSH or PULL subsciption be used?

  - by userx

  Thanks in advance for any help. I'm setting up a new Microsoft SQL Server replication and I have the Distributor and Subscriber running on the same server. The Publisher is on a remote server (as it is a production database and MS recommends that for high volumes, the Distributor should be remote). I don't know much about the inner workings of PUSH vs PULL subscriptions, but my gut tells me that a PUSH subscription would be less resource intensive because (1) the Distributor is already remote, so this shouldn't negatively effect the Publisher and (2) pushing the transactions from the Distributor to the Subscriber is more efficient than the Subscriber polling the Distribution database. Does any one have any resources or insight into PUSH vs PULL which would recommend one over the other? Is there really going to be that big of a difference in performance / reliability / security?

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• Replication of lockoutTime attribute is not urgent on AD-LDS

  - by ixe013

  I have two LDS servers on the same subnet. They replicate well. If I change an attribute, it gets replicated after 15 seconds. LDS is configured to honor password policies. When a user makes too many wrong password attemps, his account is locked and that user's lockoutTime attribute is set accordingly. But lockoutTime is not replicated as urgent. In fact, it is not replicated unless there is another change somewhere in the directory. The lockoutTime attribute will be replicated. Here is an (edited Wireshark) trace. It shows normal replication trafic No. Time Protocol Length Info 133 16:23:02 DRSUAPI 562 DsGetNCChanges request 134 16:23:02 DRSUAPI 3042 DsGetNCChanges response 152 16:23:17 DRSUAPI 562 DsGetNCChanges request 157 16:23:17 DRSUAPI 242 DsGetNCChanges response 230 16:24:57 DRSUAPI 562 DsGetNCChanges request 231 16:24:57 DRSUAPI 2930 DsGetNCChanges response 246 16:25:12 DRSUAPI 562 DsGetNCChanges request Right after that, I lock the user (with a FOR loop and ldifde). Nothing happens, until I give up and change the description attribute on the user, then about 15 seconds later I see the replication go through. 1984 16:31:05 DRSUAPI 562 DsGetNCChanges request 1985 16:31:05 DRSUAPI 2930 DsGetNCChanges response The lockoutTime and description is replicated. As stated here, if I set lockoutTime to 0, replication occurs after 15 seconds ! I have enabled replication diagnostics, but nothing shows up in the instance's logs - strange. I have enabled change notification between sites, restarted both services, but I did not see any changes. How can I make the lockoutTime replication urgent ?

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• SQL 2008 Replication over Internet

  - by Akash Kava

  We have decided to put our servers in data centers on east and west coast of US, to keep high level redundancy. After evaluating number of replication options, apart from VPN there is no other way to do replication for SQL Server. We are investigating VPN but I have following questions. Our Large DB consists of media information (pictures/movies/audio/pdf) etc, so we are not very concerned about security because they are not financial sensitive data. SQL 2005 supports or can be configured to support replication over internet? If Yes then should we downgrade to 2005? If SQL 2008 Publisher is configured for Web Sync, can we write an automatic program (C# Windows Service) to act as pull subscriber and run on the subscriber server and replicate subscriber database? Or are there any API available in SQL where we can write our own program to do replication in very generic way? (In a nut shell, can we write our own C# Windows Service based Subscriber program?)

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• Suscribers locking during snapshot replication

  - by remi_bourgarel

  Hi all :) Here is my architecture : I have a main server and 4 replica (the servers are synchronized with snapshot replication). The replication is working fine, except for one thing : during the replication a lot of SELECT request on one of the replica fail with a time-out. Here are my questions : Can I avoid these time-out ? If I can't : how can I detect the start and the end of the replication to redirect all the request on one of the replica to the main ? Thanks Sorry if you already answered to that kind of question but I couldn't find anything.

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• Schema changes with replication

  - by Even Mien

  What are the steps to make a schema change to a SQL Server 2005 database using transactional replication? I'm trying to add a database column. I thought if I removed the article for the table, made the schema change, and then added the article for the table back that the schema change would replicate. I am now getting the following error every minute or so: SQL Server errors Replication-Replication Distribution Subsystem: agent [jobname] failed. Invalid column name 'NewColumn'.

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• Is there a simple way to merge a broken 2-way-MySQL replication

  - by ~kirrus

  Hello, I have a two way replication setup, with geographically distinct servers. Replication has broken, but I don't want to just choose one as master. Is there some way to restore replication in such a way that the two databases will be re-merged?

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• MS SQL server 2005 replication

  - by hubertus

  Hi. I have a problem with replication between 3 servers. I made something like this: server A replicate (transactional replication) to server B (to 'mydb' database), then server B replicate 'mydb' (using transactional replication) to server C. On the beginning it looks and works fine, but something wrong is going on (about 2-3 month later) and replication break up. SQL say that hi can replicate db because db is allready use to replicate. Any one had similar broblem? Mayby someone knows hot can I make alternative configuration to have similar funcionality?

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• SQL Server 2008 replication failing with: process could not execute 'sp_replcmds'

  - by skb

  I have an issue with SQL replication that I am having trouble fixing. What I am doing is restoring two DBs from a production backup, and then installing replication between them. The replication seems to be configured without any errors, but when I look at the status I see error messages like this: I have an issue with SQL replication that I am having trouble fixing. What I am doing is restoring two DBs from a production backup, and then installing replication between them. The replication seems to be configured without any errors, but when I look at the status in Replication Monitor I see error messages like this: Error messages: The process could not execute 'sp_replcmds' on 'MYSERVER1'. Get help: http://help/MSSQL_REPL20011 Cannot execute as the database principal because the principal "dbo" does not exist, this type of principal cannot be impersonated, or you do not have permission. (Source: MSSQLServer, Error number: 15517) Get help: http://help/15517 The process could not execute 'sp_replcmds' on 'MYSERVER1'. Get help: http://help/MSSQL_REPL22037 What does this mean?

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• Big Data – Various Learning Resources – How to Start with Big Data? – Day 20 of 21

  - by Pinal Dave

  In yesterday’s blog post we learned how to become a Data Scientist for Big Data. In this article we will go over various learning resources related to Big Data. In this series we have covered many of the most essential details about Big Data. At the beginning of this series, I have encouraged readers to send me questions. One of the most popular questions is - “I want to learn more about Big Data. Where can I learn it?” This is indeed a great question as there are plenty of resources out to learn about Big Data and it is indeed difficult to select on one resource to learn Big Data. Hence I decided to write here a few of the very important resources which are related to Big Data. Learn from Pluralsight Pluralsight is a global leader in high-quality online training for hardcore developers.  It has fantastic Big Data Courses and I started to learn about Big Data with the help of Pluralsight. Here are few of the courses which are directly related to Big Data. Big Data: The Big Picture Big Data Analytics with Tableau NoSQL: The Big Picture Understanding NoSQL Data Analysis Fundamentals with Tableau I encourage all of you start with this video course as they are fantastic fundamentals to learn Big Data. Learn from Apache Resources at Apache are single point the most authentic learning resources. If you want to learn fundamentals and go deep about every aspect of the Big Data, I believe you must understand various concepts in Apache’s library. I am pretty impressed with the documentation and I am personally referencing it every single day when I work with Big Data. I strongly encourage all of you to bookmark following all the links for authentic big data learning. Haddop - The Apache Hadoop® project develops open-source software for reliable, scalable, distributed computing. Ambari: A web-based tool for provisioning, managing, and monitoring Apache Hadoop clusters which include support for Hadoop HDFS, Hadoop MapReduce, Hive, HCatalog, HBase, ZooKeeper, Oozie, Pig and Sqoop. Ambari also provides a dashboard for viewing cluster health such as heat maps and ability to view MapReduce, Pig and Hive applications visually along with features to diagnose their performance characteristics in a user-friendly manner. Avro: A data serialization system. Cassandra: A scalable multi-master database with no single points of failure. Chukwa: A data collection system for managing large distributed systems. HBase: A scalable, distributed database that supports structured data storage for large tables. Hive: A data warehouse infrastructure that provides data summarization and ad hoc querying. Mahout: A Scalable machine learning and data mining library. Pig: A high-level data-flow language and execution framework for parallel computation. ZooKeeper: A high-performance coordination service for distributed applications. Learn from Vendors One of the biggest issues with about learning Big Data is setting up the environment. Every Big Data vendor has different environment request and there are lots of things require to set up Big Data framework. Many of the users do not start with Big Data as they are afraid about the resources required to set up framework as well as a time commitment. Here Hortonworks have created fantastic learning environment. They have created Sandbox with everything one person needs to learn Big Data and also have provided excellent tutoring along with it. Sandbox comes with a dozen hands-on tutorial that will guide you through the basics of Hadoop as well it contains the Hortonworks Data Platform. I think Hortonworks did a fantastic job building this Sandbox and Tutorial. Though there are plenty of different Big Data Vendors I have decided to list only Hortonworks due to their unique setup. Please leave a comment if there are any other such platform to learn Big Data. I will include them over here as well. Learn from Books There are indeed few good books out there which one can refer to learn Big Data. Here are few good books which I have read. I will update the list as I will learn more. Ethics of Big Data Balancing Risk and Innovation Big Data for Dummies Head First Data Analysis: A Learner’s Guide to Big Numbers, Statistics, and Good Decisions If you search on Amazon there are millions of the books but I think above three books are a great set of books and it will give you great ideas about Big Data. Once you go through above books, you will have a clear idea about what is the next step you should follow in this series. You will be capable enough to make the right decision for yourself. Tomorrow In tomorrow’s blog post we will wrap up this series of Big Data. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Big Data, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL

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• Data Storage Options

  - by Kenneth

  When I was working as a website designer/engineer I primarily used databases for storage of much of my dynamic data. It was very easy and convenient to use this method and seemed like a standard practice from my research on the matter. I'm now working on shifting away from websites and into desktop applications. What are the best practices for data storage for desktop applications? I ask because I have noticed that most programs I use on a personal level don't appear to use a database for data storage unless its embedded in the program. (I'm not thinking of an application like a word processor where it makes sense to have data stored in individual files as defined by the user. Rather I'm thinking of something more along the lines of a calendar application which would need to store dates and event info and such where accessing that information would be much easier if stored in a database... at least as far as my experience would indicate.) Thanks for the input!

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• What is a Data Warehouse?

  Typically Data Warehouses are considered to be non-volatile in comparison to traditional databasesdue to the fact that data within the warehouse does not change that often.  In addition, Data Warehouses typically represent data through the use of Multidimensional Conceptual Views that allow data to be extracted based on the view and the current position within the view. Common Data Warehouse Traits Relatively Non-volatile Data Supports Data Extraction and Analysis Optimized for Data Retrieval and Analysis Multidimensional Views of Data Flexible Reporting Multi User Support Generic Dimensionality Transparent Accessible Unlimited Dimensions of Data Unlimited Aggregation levels of Data Normally, Data Warehouses are much larger then there traditional database counterparts due to the fact that they store the basis data along with derived data via Multidimensional Conceptual Views. As companies store larger and larger amounts of data, they will need a way to effectively and accurately extract analysis information that can be used to aide in formulating current and future business decisions. This process can be done currently through data mining within a Data Warehouse. Data Warehouses provide access to data derived through complex analysis, knowledge discovery and decision making. Secondly, they support the demands for high performance in regards to analyzing an organization’s existing and current data. Data Warehouses provide support for an organization’s data and acquired business knowledge.  Within a Data Warehouse multiple types of operations/sub systems are supported. Common Data Warehouse Sub Systems Online Analytical Processing (OLAP) Decision –Support Systems (DSS) Online Transaction Processing (OLTP)

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• How Do You Actually Model Data?

  Since the 1970’s Developers, Analysts and DBAs have been able to represent concepts and relations in the form of data through the use of generic symbols.  But what is data modeling?  The first time I actually heard this term I could not understand why anyone would want to display a computer on a fashion show runway. Hey, what do you expect? At that time I was a freshman in community college, and obviously this was a long time ago.  I have since had the chance to learn what data modeling truly is through using it. Data modeling is a process of breaking down information and/or requirements in to common categories called objects. Once objects start being defined then relationships start to form based on dependencies found amongst other existing objects.  Currently, there are several tools on the market that help data designer actually map out objects and their relationships through the use of symbols and lines.  These diagrams allow for designs to be review from several perspectives so that designers can ensure that they have the optimal data design for their project and that the design is flexible enough to allow for potential changes and/or extension in the future. Additionally these basic models can always be further refined to show different levels of details depending on the target audience through the use of three different types of models. Conceptual Data Model(CDM)Conceptual Data Models include all key entities and relationships giving a viewer a high level understanding of attributes. Conceptual data model are created by gathering and analyzing information from various sources pertaining to a project during the typical planning phase of a project. Logical Data Model (LDM)Logical Data Models are conceptual data models that have been expanded to include implementation details pertaining to the data that it will store. Additionally, this model typically represents an origination’s business requirements and business rules by defining various attribute data types and relationships regarding each entity. This additional information can be directly translated to the Physical Data Model which reduces the actual time need to implement it. Physical Data Model(PDMs)Physical Data Model are transformed Logical Data Models that include the necessary tables, columns, relationships, database properties for the creation of a database. This model also allows for considerations regarding performance, indexing and denormalization that are applied through database rules, data integrity. Further expanding on why we actually use models in modern application/database development can be seen in the benefits that data modeling provides for data modelers and projects themselves, Benefits of Data Modeling according to Applied Information Science Abstraction that allows data designers remove concepts and ideas form hard facts in the form of data. This gives the data designers the ability to express general concepts and/or ideas in a generic form through the use of symbols to represent data items and the relationships between the items. Transparency through the use of data models allows complex ideas to be translated in to simple symbols so that the concept can be understood by all viewpoints and limits the amount of confusion and misunderstanding. Effectiveness in regards to tuning a model for acceptable performance while maintaining affordable operational costs. In addition it allows systems to be built on a solid foundation in terms of data. I shudder at the thought of a world without data modeling, think about it? Data is everywhere in our lives. Data modeling allows for optimizing a design for performance and the reduction of duplication. If one was to design a database without data modeling then I would think that the first things to get impacted would be database performance due to poorly designed database and there would be greater chances of unnecessary data duplication that would also play in to the excessive query times because unneeded records would need to be processed. You could say that a data designer designing a database is like a box of chocolates. You will never know what kind of database you will get until after it is built.

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• Data Structures usage and motivational aspects

  - by Aubergine

  For long student life I was always wondering why there are so many of them yet there seems to be lack of usage at all in many of them. The opinion didn't really change when I got a job. We have brilliant books on what they are and their complexities, but I never encounter resources which would actually give a good hint of practical usage. I perfectly understand that I have to look at problem , analyse required operations, look for data structure that does them efficiently. However in practice I never do that, not because of human laziness syndrome, but because when it comes to work I acknowledge time priority over self-development. Over time I thought that when I would be better developer I will automatically use more of them - that didn't happen at all or maybe I just didn't. Then I found that the colleagues usually in the same plate as me - knowing more or less some three of data structures and being totally happy about it and refusing to discuss this matter further with me, coming back to conversations about 'cool new languages' 'libraries that do jobs for you' and the joy to work under scrumban etc. I am stuck with ArrayLists, Arrays and SortedMap , which no matter what I do always suffice or either I tweak them to be capable of fulfilling my task. Yes, it might be inefficient but do we really have to care if Intel increases performance over years no matter if we improve our skills? Does new Xeon or IBM machines really care what we use? What if I like build things, but I am not particularly excited whether it is n log(n) or just n? Over twenty years the processing power increased enormously, which gives us freedom of not being critical about which one to use? On top of that new more optimized languages appear which support multiple cores more efficiently. To be more specific: I would like to find motivational material on complex real areas/cases of possible effective usages of data structures. I would be really grateful if you would provide relevant resources. There is similar question ,but in the end the links again mostly describe or do dumb example(vehicles, students or holy grail quest - yes, very relevant) them and people keep referring to the "scenario decides the data structure to use". I want to know these complex scenarios to be able to identify similarities to my scenario and then use them. The complex scenarios where it really matters and not necessarily of quantitive nature. It seems that data structures only concern is efficiency and nothing else? There seems to be no particular convenience for developer in use one over another. (only when I found scientific resources on why exactly simple carbohydrates are evil I stopped eating sugar and candies completely replacing it with less harmful fruits - I hope you can see the analogy)

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• Unleash AutoVue on Your Unmanaged Data

  - by [email protected]

  Over the years, I've spoken to hundreds of customers who use AutoVue to collaborate on their "managed" data stored in content management systems, product lifecycle management systems, etc. via our many integrations. Through these conversations I've also learned a harsh reality - we will never fully move away from unmanaged data (desktops, file servers, emails, etc). If you use AutoVue today you already know that even if your primary use is viewing content stored in a content management system, you can still open files stored locally on your computer. But did you know that AutoVue actually has - built-in - a great solution for viewing, printing and redlining your data stored on file servers? Using the 'Server protocol' you can point AutoVue directly to a top-level location on any networked file server and provide your users with a link or shortcut to access an interface similar to the sample page shown below. Many customers link to pages just like this one from their internal company intranets. Through this webpage, users can easily search and browse through file server data with a 'click-and-view' interface to find the specific image, document, drawing or model they're looking for. Any markups created on a document will be accessible to everyone else viewing that document and of course real-time collaboration is supported as well. Customers on maintenance can consult the AutoVue Admin guide or My Oracle Support Doc ID 753018.1 for an introduction to the server protocol. Contact your local AutoVue Solutions Consultant for help setting up the sample shown above.

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• SQL SERVER – Step by Step Guide to Beginning Data Quality Services in SQL Server 2012 – Introduction to DQS

  - by pinaldave

  Data Quality Services is a very important concept of SQL Server. I have recently started to explore the same and I am really learning some good concepts. Here are two very important blog posts which one should go over before continuing this blog post. Installing Data Quality Services (DQS) on SQL Server 2012 Connecting Error to Data Quality Services (DQS) on SQL Server 2012 This article is introduction to Data Quality Services for beginners. We will be using an Excel file Click on the image to enlarge the it. In the first article we learned to install DQS. In this article we will see how we can learn about building Knowledge Base and using it to help us identify the quality of the data as well help correct the bad quality of the data. Here are the two very important steps we will be learning in this tutorial. Building a New Knowledge Base  Creating a New Data Quality Project Let us start the building the Knowledge Base. Click on New Knowledge Base. In our project we will be using the Excel as a knowledge base. Here is the Excel which we will be using. There are two columns. One is Colors and another is Shade. They are independent columns and not related to each other. The point which I am trying to show is that in Column A there are unique data and in Column B there are duplicate records. Clicking on New Knowledge Base will bring up the following screen. Enter the name of the new knowledge base. Clicking NEXT will bring up following screen where it will allow to select the EXCE file and it will also let users select the source column. I have selected Colors and Shade both as a source column. Creating a domain is very important. Here you can create a unique domain or domain which is compositely build from Colors and Shade. As this is the first example, I will create unique domain – for Colors I will create domain Colors and for Shade I will create domain Shade. Here is the screen which will demonstrate how the screen will look after creating domains. Clicking NEXT it will bring you to following screen where you can do the data discovery. Clicking on the START will start the processing of the source data provided. Pre-processed data will show various information related to the source data. In our case it shows that Colors column have unique data whereas Shade have non-unique data and unique data rows are only two. In the next screen you can actually add more rows as well see the frequency of the data as the values are listed unique. Clicking next will publish the knowledge base which is just created. Now the knowledge base is created. We will try to take any random data and attempt to do DQS implementation over it. I am using another excel sheet here for simplicity purpose. In reality you can easily use SQL Server table for the same. Click on New Data Quality Project to see start DQS Project. In the next screen it will ask which knowledge base to use. We will be using our Colors knowledge base which we have recently created. In the Colors knowledge base we had two columns – 1) Colors and 2) Shade. In our case we will be using both of the mappings here. User can select one or multiple column mapping over here. Now the most important phase of the complete project. Click on Start and it will make the cleaning process and shows various results. In our case there were two columns to be processed and it completed the task with necessary information. It demonstrated that in Colors columns it has not corrected any value by itself but in Shade value there is a suggestion it has. We can train the DQS to correct values but let us keep that subject for future blog posts. Now click next and keep the domain Colors selected left side. It will demonstrate that there are two incorrect columns which it needs to be corrected. Here is the place where once corrected value will be auto-corrected in future. I manually corrected the value here and clicked on Approve radio buttons. As soon as I click on Approve buttons the rows will be disappeared from this tab and will move to Corrected Tab. If I had rejected tab it would have moved the rows to Invalid tab as well. In this screen you can see how the corrected 2 rows are demonstrated. You can click on Correct tab and see previously validated 6 rows which passed the DQS process. Now let us click on the Shade domain on the left side of the screen. This domain shows very interesting details as there DQS system guessed the correct answer as Dark with the confidence level of 77%. It is quite a high confidence level and manual observation also demonstrate that Dark is the correct answer. I clicked on Approve and the row moved to corrected tab. On the next screen DQS shows the summary of all the activities. It also demonstrates how the correction of the quality of the data was performed. The user can explore their data to a SQL Server Table, CSV file or Excel. The user also has an option to either explore data and all the associated cleansing info or data only. I will select Data only for demonstration purpose. Clicking explore will generate the files. Let us open the generated file. It will look as following and it looks pretty complete and corrected. Well, we have successfully completed DQS Process. The process is indeed very easy. I suggest you try this out yourself and you will find it very easy to learn. In future we will go over advanced concepts. Are you using this feature on your production server? If yes, would you please leave a comment with your environment and business need. It will be indeed interesting to see where it is implemented. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Business Intelligence, Data Warehousing, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology Tagged: Data Quality Services, DQS

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• Consolidate Data in Private Clouds, But Consider Security and Regulatory Issues

  - by Troy Kitch

  The January 13 webcast Security and Compliance for Private Cloud Consolidation will provide attendees with an overview of private cloud computing based on Oracle's Maximum Availability Architecture and how security and regulatory compliance affects implementations. Many organizations are taking advantage of Oracle's Maximum Availability Architecture to drive down the cost of IT by deploying private cloud computing environments that can support downtime and utilization spikes without idle redundancy. With two-thirds of sensitive and regulated data in organizations' databases private cloud database consolidation means organizations must be more concerned than ever about protecting their information and addressing new regulatory challenges. Join us for this webcast to learn about greater risks and increased threats to private cloud data and how Oracle Database Security Solutions can assist in securely consolidating data and meet compliance requirements. Register Now.

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• Validating Data Using Data Annotation Attributes in ASP.NET MVC

  - by bipinjoshi

  The data entered by the end user in various form fields must be validated before it is saved in the database. Developers often use validation HTML helpers provided by ASP.NET MVC to perform the input validations. Additionally, you can also use data annotation attributes from the System.ComponentModel.DataAnnotations namespace to perform validations at the model level. Data annotation attributes are attached to the properties of the model class and enforce some validation criteria. They are capable of performing validation on the server side as well as on the client side. This article discusses the basics of using these attributes in an ASP.NET MVC application.http://www.bipinjoshi.net/articles/0a53f05f-b58c-47b1-a544-f032f5cfca58.aspx       

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• Setup MSSQL replication with peer to peer topology: problem setting up Conflict Detection

  - by Roel

  Hi, I'm setting up a SQL Replication strategy, using MSSQL2008 with peer-to-peer publications (2 servers, each one subscribes to the other). I followed this HOWTO from MSDN, and the setup seems to be working fine: add a record to one table on server A, query on server B shows the new record. So far, so good. So far I only have one table 'Templates': Id PK (calculated field) NodeId int default 1/2 (Server A = 1, Server B = 2) LocalId int autoid Name nvarchar(100) Now, I would like to enable 'Conflict detection', which should be enabled by default. But every time I try to save the 'Conflict Detection' feature in the Publication Properties I get the following error: Cannot save Peer conflict detection properties. An exception occurred while executing a Transact-SQL statement or batch.(Microsoft.SqlServer.ConnectionInfo) Program Location: at Microsoft.SqlServer.Management.Common.ServerConnection.ExecuteNonQuery(String sqlCommand, ExecutionTypes executionType) at Microsoft.SqlServer.Management.Common.ServerConnection.ExecuteNonQuery(String sqlCommand) at Microsoft.SqlServer.Replication.ReplicationObject.ExecCommand(String commandIn) at Microsoft.SqlServer.Replication.TransPublication.SetPeerConflictDetection(Boolean enablePeerConflictDetection, Int32 peerOriginatorID) at Microsoft.SqlServer.Management.UI.PubPropSubscriptionOptions.SaveP2PConflictDetection() at Microsoft.SqlServer.Management.UI.PubPropSubscriptionOptions.SaveProperties(ExecutionMode& executionResult) Column name 'Id' does not exist in the target table or view. Changed database context to 'TestDB'. (.Net SqlClient Data Provider) For help, click: http://go.microsoft.com/fwlink?ProdName=Microsoft+SQL+Server&ProdVer=10.00.2531&EvtSrc=MSSQLServer&EvtID=1911&LinkId=20476 Server Name: SERVER_A Error Number: 1911 Severity: 16 State: 1 Line Number: 2 Program Location: at System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection) at System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection) at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj) at System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj) at System.Data.SqlClient.SqlCommand.RunExecuteNonQueryTds(String methodName, Boolean async) at System.Data.SqlClient.SqlCommand.InternalExecuteNonQuery(DbAsyncResult result, String methodName, Boolean sendToPipe) at System.Data.SqlClient.SqlCommand.ExecuteNonQuery() at Microsoft.SqlServer.Management.Common.ServerConnection.ExecuteNonQuery(String sqlCommand, ExecutionTypes executionType) Now, I googled the hell out of this error, and nothing shows up. I also can't seem to find out what the exact target table of the error "Column name 'Id' does not exist..." is. Has anyone every done this successfully? Am I missing something? Having this setup without conflict detection feels pretty useless... EDIT OK, so after some more research and setting up with different databases etc, I found out that the calculated 'Id' column of the Templates table is the culprit. I don't know why, but the replication doesn't seem to allow calculated columns (which are also primary key). It works now too, without the 'Id' column, and using the NodeId and LocalId as a combined PK. So now the question is, why isn't it allowed to have a calculated column as PK for replication with conflict detection?

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